Circuit breaker for motor vehicles



Jan. 23, 1940. F. A. EYTMAN CIRCUIT BREAKER FOR MOTOR VEHICLES Filed April 22, 1938 INVENTOR v J'TA.Eyf/1na1z Patented Jan. 23, 1940 UNITED} STATES PATENT OFFICE CIRCUIT BREAKER FOR MOTOR VEHICLES Frank A. Eytman, Turlock, Calif.

Application April 22, 1938, Serial No. 203,563

4 Claims. (Cl. 200-52) This invention relates to a circuit breaker for motor vehicles and in particular is directed to a circuit breaker arranged to function by reason of the impact shock imparted to the device when the vehicle to which it is attached is involved in an accident and strikes another object.

The objects of the present invention are substantially those specified in my copending application for U. S. Patent Serial No. 146,605, filed June 5, 1937; and, in addition, it is my purpose to provide a device of the character described, which-when properly adjusted-will not be affected by road shocks, brake application, or incidental bumper shocks.

It is also my object to provide a circuit breaker which is sensitive to adjustment and has a relatively great range of adjustment; that is, the device can be adjusted to operate at any shock intensity through a relatively great range.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly efiective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Figure 1 is a sectional elevation of the device in a set position, and with the contact points engaged.

Figure 2 is a section taken on line 2-2 of Figure 1, and illustrates the device after actuation thereof and in circuit breaking position.

Figure 3 is a plan view with the upper cap removed, and the control pin in section.

Referring now more particularly to the characters of reference on the drawing, the device comprises a cylindrical,, initially open ended body I provided with an upper cap 2 and a lower cap 3 threaded on the body. Mounting flanges 4 project tangentially from the body, in opposite directions.

The body is separated on the inside into upper and lower chambers by means of a wall 5 fixed in place some distance above the center of length of said body as shown.

A stem 6 is normally disposed in vertical position centrally in the lower chamber, said stem being centrally mounted in upstanding relation on a disc 1 which rests upon a concentric annular flange 8 upstanding from the inner face of the lower cap 3. A concentric locating element 9 de,

pends from disc 1 into the area surrounded by flange 8. The edge of element 9 tapers inwardly from the disc downward as at H]. By beveling the edge, disc 7 can rock on flange 8 without restriction, but cannot escape therefrom as illustrated in Fig. 2, and for the purpose hereinafter described.

A solid metal member ll, of cylindrical configuration, is provided with an axial bore and is adjustably secured on stem 6. The upper end of the stem terminates adjacent but clear of wall 5. An annular and concentric flange I2 depends from the wall into the lower chamber and in surrounding relation to the upper end of the stem.

A centrally disposed pin l3 slidably extends through cap 2 and wall 5; the lower end of the pin normally resting atop stem 6 in end to end engagement therewith. A compression spring l4 surrounds the pin between cap 2 and a collar l5 fixed on the pin. This spring urges the pin downward at all times. At a point some distance above the upper face of wall 5, the pin is tapered down to smaller diameter forming a cam surface I6.

A contact arm I! is pivoted as at l8, on the upper surface of wall 5, and carries a contact point l9 which normally engages a complementary contact point 20 on a fixed support 2| by reason of the influence of a tension spring 22. Arm I7 and support 2| are insulated from Wall 5 in any suitable manner. The arm I! is disposed relative to pin l3 so that a dielectric cam element 23, fixed on and projecting from the arm intermediate its ends, normally underhangs the cam surface l6. While the present embodiment shows one contact point carried on a fixed support, both may be carried on movable contact arms if desired. Binding posts 24 are mounted on the body and one is connected with the contact arm I! and the other with support 2| by wires 25.

In use, the device is mounted on a motor vehicle in vertical position, and the contact unit is interposed in the motor ignition circuit. The several parts of the device are normally positioned as in Fig. 1, and when in such position the circuit is closed. However, upon the occurrence of an impact shock of sufficient intensity, member M will throw to one side or the other, tilting stem 6 from beneath pin l3. Pin [3 then falls and cam element 23 is moved outward by cam surface I 6, separating points I 9 and 20 and breaking the circuit.

Flange l2 limits tipping movement of the stem at the upper end, while element 9 maintains disc 1 against lateral movement. The pin l3 being lowered alongside the upper end of stem 6 prevents the latter returning to a normal position after being once tilted. To reset the device, pin I3 is raised manually and stem 6 rocks back of itself to a normal vertical position.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

'1. In a circuit breaker including a pair of normally engaged but separable contact points, one-of said contact points being mounted on a movable horizontal arm, a cam element on the arm, a vertical axially movable spring pressed pin having a bevel portion intermediate its ends and forming a cam surface, said surface being adapted to engage the cam and move the arm horizontally in a direction to separate the points upon lowering movement of the pin, and a. tiltable unit disposed below the pin and including a normally upstanding stem; said stem when in an upstanding position, releasably engaging the lower end of the pin and holding the same in a raised position with the cam free of said cam surface, the stem releasing the pin upon tilting of the unit under the influence of an impact shock.

2. A circuit breaker including a pair of normally engaged but separable contact points, normally inactive means arranged to separate said points, and a tiltable unit, said means being arranged to function with and to be controlled by tilting of the unit; said unit comprising a normally upstanding stem, a relatively heavy member surrounding the stem intermediate its ends in concentric relation, and a circular supporting disc secured on the lower end of the stem at right angles thereto.

3. A device as in claim 2, including an annular flange upon which the disc is disposed, a circular locating element depending from the disc within the flange; the peripheral edge of said element at the disc being of a diameter substantially that of the flange, and tapering inwardly from the disc downward 4. A circuit breaker comprising a vertical pin guided for axial movement, a spring tending to lower the pin, a pair of normally engaged contact points laterally offset from the pin, means actuated by lowering of the pin to separate the points and means normally holding the pin against lowering movement and comprising a vertical stem below and normally alined with the pin and engaging the lower end thereof, a disc rigid with the lower end of the stem and centered thereon, a fixed supporting flange engaging the disc about its periphery and a weight on the stem above the disc.

FRANK A. EYTMAN. 

